Title of Invention

A METHOD OF REMOVING CONTAMINANTS FROM A CONTAMINATED PROCESS STREAM

Abstract A method for removing contaminants from a process stream that includes the use of reticulated material to filter the process stream. The reticulated material also facilitate process stream flow distribution in process units. The reticu- lated material can be packed with a void space between a substantia] number of the reticulated material that can be varied to enhance filtration and flow distribution. The method of filtering also provides a method of removing contaminants leaving process equipment. The methods can be used on a variety of process streams and process equipment. The reticulated material can include ceramics, metallic mate- rials, and chemical vapor deposition elements. The reticulated material can be of various shapes and sizes, and can also be catalytically active.
Full Text FILTRATION, FLOW DISTRIBUTION AND CATALYTIC
METHOD FOR PROCESS STREAMS
BACKGROUND OF THE INVENTION
1. Field Of The Invention
[0001] The invention relates to a method of providing filtration of contaminants from
process streams. In another aspect, this invention relates to a method for providing
flow distribution of process streams in process units. In yet another aspect, this
invention provides filtration or flow distribution or both while concurrently catalyzing
at least one reaction to at least partially remove and/or convert certain chemical
species within the process stream.
2. Description Of Related Art
[0002] Contaminants in process streams can be deleterious to processes and also to
process units. Contaminants can damage process units, potentially resulting in an
environmental or safety incident. Contaminants can also damage processes by
decreasing efficiencies within processes, stopping production, affecting the
specifications of products, or the like. Contaminants can be found in all types of
process streams, such as feed streams, discharge streams, or effluent streams.
Contaminants can affect various types of process units , such as reactors, extractors,
distillation columns, scrubbers, tail gas treaters, incinerators, exchangers, boilers,
condensers, and the like.
[0003] Process units may be configured such that process streams in the unit flows
vertically downward or upward or both. Alternatively, process streams in the unit
may flow radially from the center out or from the external part of the unit to the center
or both.
[0004] Reactors are one type of process unit Many reactors include discrete solid
catalyst particles contained in one or more fixed beds. Catalyst beds are typically
very efficient at trapping contaminants in process streams fed to the catalyst bed.
Such catalyst beds, however, can quickly become clogged by these trapped
contaminants. As the bed becomes clogged, pressure drop across the process unit
rises resulting in eventual premature shutdown of the process unit.
[0005] Partly to mitigate this problem, catalyst bed process units as well as non-
catalyst bed process units are often supplemented with conventional retention material
beds that are somewhat less resistant to clogging. These conventional retention
material beds are typically located at the inlet to the process unit In the case of
catalyst bed process units, the conventional retention material beds are typically inert
to the reactions in the catalyst bed. These conventional retention material beds can be
somewhat effective in trapping or filtering all or some contaminants such as dirt, iron
oxide, iron sulfide, asphaltenes, coke fines, catalyst fines, sediments or other entrained
foreign particulate material in the process stream entering, within or leaving the
process unit. The trapping of the contaminants is to prevent undesirable material from
clogging or poisoning or otherwise harming the process unit. When these
conventional retention material beds are inert they are typically made of conventional
ceramic materials in the form of pellets, rings, saddles or spheres and typically must
be resistant to crushing, high temperatures and/or high pressures. While these
conventional retention material beds can be somewhat effective in preventing the
process unit from being clogged, the conventional retention material beds themselves
eventually become clogged.
[0006] Conventional retention material beds may also facilitate flow distribution of
the process stream in a direction perpendicular to the flow of the process stream
across the process unit Such behavior will be referred to herein as perpendicular
flow distribution. As an example, in an upflow or downflow process unit, the process
stream flow is in the axial direction and the perpendicular flow distribution is in the
radial direction.
[0007] To increase the efficiency of conventional retention material beds, graduated
layers of these materials in different sizes and shapes along with perforated discs, or
screen baskets, have been used to retard the process unit from becoming clogged with
contaminants such as dirt, iron oxide, iron sulfide, asphaltenes, coke fines, catalyst
fines, sediments, or other entrained foreign particulate material.
[0008] Conventional retention material beds exposed to contaminants at the inlet to a
process unit will eventually become clogged with contaminants. As this happens, the
pressure drop across the process unit rises, resulting in the eventual shutdown of the
unit. When this happens in catalyst bed process units, it is typical that part of the
catalyst bed itself becomes somewhat or completely clogged with contaminants.
After such shutdown of the process unit, skimming, or removal, of the clogged
portion of the conventional retention material, as well as the clogged portion of the
catalyst bed, is required.
[0009] In addition to clogging by contaminants in the process stream, polymerization
of polymer precursors, e.g., diolefins, found in the process streams fed to catalyst bed
process units may also foul, gum or plug such process units. In particular, two
mechanisms of polymermtion, free radical polymerization and condensation-type
polymerization, may cause catalyst bed fouling, gumming or plugging. The addition
of antioxidants to control free radical polymerization has been found useful where the
process stream has encountered oxygen. Condensation polymerization of diolefins
typically occurs after an organic-based feed is heated. Therefore, filtering prior to the
process stream entering the catalyst bed process unit may not be helpful to remove
these foulants as the polymerization reactions generally take place in the unit.
[0010] It is highly desirable to have retention materials that do not just clog with
contaminants but efficiently and effectively filter contaminants from the process
stream. Efficiency relates to the percent of contaminants removed by such materials
from the process stream, as well as, to the range of sizes of contaminants that can be
removed by such materials. Effectiveness relates to the extent that such materials do
not impede the flow of the decontaminated process stream through the retention
materials. Such materials would desirably remove virtually all contaminants within a
broad range of sizes from the process stream, while not causing an unacceptable
pressure drop increase across the process unit. It is also highly desirable to have
retention materials that promote perpendicular flow distribution. The method of the
present invention for filtration and flow distribution for process streams, when
compared with previously proposed prior art methods, has the advantages of
providing highly efficient and highly effective filtering of contaminants; increasing
the life and activity of catalysts in catalyst bed process units; decreasing catalyst
losses; allowing for the optimization of process unit configuration; improving the
perpendicular flow distribution of process streams into and within process units and
eliminating the need to take process units off-line when conventional retention
material beds have clogged to the point that pressure drop across units have risen to
unacceptable levels. These benefits may result in both capital and operating cost
savings, reduced downtimes, increased process unit performance and extended
process unit operating time.
[0011] Weaknesses of conventional retention material beds are that they are neither
particularly efficient nor particularly effective as filters. Conventional retention
material beds are typically efficient at removing some contaminants from the process
stream for a limited period of time. The contaminants so trapped are typically those
about 50 microns and larger. The effectiveness of conventional retention material
beds suffers due to eventual clogging, which prevents flow of the decontaminated
process stream through the conventional retention material beds and leads to
unacceptable increase in process unit pressure drop. Furthermore, conventional
retention material beds appear to trap contaminants within about the top six to twelve
inches of depth. Deeper beds of conventional retention materials do not increase the
trapping capacity of these materials. Therefore, the art has sought filtration methods
that remove particulate contaminants smaller than 50 microns, that filter particulate
contaminants while allowing the free flow of decontaminated process streams with no
significant rise in process unit pressure drop and that have a filtering capacity that
increases with bed depth, regardless of bed depth.
[0012] Disadvantages associated with current perpendicular flow distribution designs
and methods in process units may result in poor distribution within the process unit
Clogging or other fouling such as that caused by particulate contaminants or the
products of undesired polymerization reactions may also cause maldistribution. The
maldistribution may result in channeling and corresponding bypassing of portions of
the process unit, reduction in the efficiency of contaminant removal and reduction in
unit efficiency. Usually, a maldistribution problem is also evidenced by so-called
temperature hot-spots. Such hot-spots can, for example, lead to increased coking and
reduced activity in catalyst bed process units. Therefore, the art has sought a
perpendicular flow distribution method that may distribute the process stream more
uniformly within the process unit, provide efficient filtering of contaminants, reduce
the occurrence of hot-spots and reduce fouling caused by undesired polymerization
reactions.
[0013] U.S. Patent Nos. 6,258,900 and 6,291,603, both of which are incorporated by
reference in their entireties, describe reticulated ceramic materials that are used to
filter and distribute organic feed streams in a chemical reactor. A need exists for
filtering and flow distribution capabilities for other types of process streams besides
organic-based streams and for other types of process units besides chemical reactors.
[0014] It is desirable for the filtering and flow distribution methods for all process
streams and all process units to increase the filtering efficiency and effectiveness of
materials utilized to remove contaminants from process streams, to improve
perpendicular flow distribution within process units, to have unit run length
determined by factors other than pressure drop increase, to minimize pressure drops
across process equipment, and to minimize process safety and environmental
concerns arising from catalyst bed channeling and flow maldistribution, temperature
hot-spots and process unit shutdowns and start-ups.
SUMMARY OF INVENTION
[0015] In accordance with the invention, the foregoing advantages have been
achieved through the present method of filtering a process stream, for distributing a
process stream within a process unit and for accomplishing one or both while
concurrently catalyzing desired reactions using reticulated elements. The present
invention advantageously provides a method of removing contaminants from a
contaminated process stream. The method preferably is performed by passing the
process stream over a plurality of reticulated elements in a process unit. The
reticulated elements are randomly packed in the process unit such that there is
significant void space between each reticulated element to enhance filtration of
contaminants on a surface of the reticulated elements while allowing the
decontaminated process stream to pass unimpeded through the plurality of reticulated
elements. A surface can include an inner surface and an outer surface. Reticulated
elements made in accordance with the present invention will have more inner surface
area available for filtering than outer surface area. Reticulated elements can include
foam materials and monolith materials. Foam materials generally have a random
partern, while the monoliths have a more uniform partem. The reticulated elements
can be made from any commercially available materials, for example, zirconia
toughened alumina, commonly referred to as ZTA. ZTA is available, in a ceramic
foam, from Fiber Ceramics, Inc. headquartered in Cudahy, Wisconsin. Another
suitable type of ceramic is a monolith, which is manufactured by Coming, Inc.
headquartered in Coming, New York. The process stream can be a liquid stream, a
vapor phase, or a combination of both phases, and the contaminants can include dirt,
iron oxide, iron sulfide, asphaltenes, coke fines, soot, catalyst fines, sediments or
other entrained foreign particulate matter, salts in distillation columns, particulates in
gas streams, or sulfur or sulfides from tail gas units. The process stream can also be
an organic-based process stream. The reticulated elements should be provided in an
amount sufficient to remove some or all of the contaminants from the process stream.
Another feature of the present invention may include the step of providing a
decontaminated process stream for further processing.
[0016] More particularly, the invention relates to a process for improving stream
quality of process streams entering to process units. An exemplary example includes
improving stream quality of organic-based process streams going to catalytic bed
process units. Preferably, the catalytic bed process units use discrete, solid element,
fixed catalyst beds. The catalytic bed process units can include hydrotreater,
hydrorefiner, hydrocracker, reformer, alkylation, dealkylation, isomerization,
oxidation, esterification, and polymerization reactors. The discrete solid catalyst
particles may be contained in one or more fixed beds and in either an upflow,
downflow or radial flow design.
[0017] In addition to catalytic bed process units, the reticulated elements of the
present invention can be used to remove contaminants from other types of process
equipment. Such process equipment can include incinerators, scrubbers, tail gas
treaters, and distillation columns and any manufacturing units that operate in a
continuous fashion. When used in a distillation column, the reticulated elements can
be placed in the bottom of the distillation column to act as a filter to remove salts
from the distillation process. Removal of salts will reduce the pressure drop across
the tower, allow for better separation efficiency in the column, and increase the time
between downtimes typically required to remove these salts from the column.
[0018] The present invention also advantageously provides a method of perpendicular
flow distribution in process units. This perpendicular flow distribution method
includes providing one or more reticulated elements in the process unit. When only
one reticulated element is used, it is typically large enough to effectively span the
process unit. When multiple reticulated elements are used, they are typically arranged
in a randomly packed bed. Regardless of the configuration of the reticulated
elements, each reticulated element has a plurality of web members that define a
plurality of flow passageways through the reticulated element. A process stream
contacted with the plurality of reticulated elements is therefore subdivided into a
plurality of smaller fluid streams by passing the process stream through the plurality
of flow passageways defined by the web members of each reticulated element. The
flows of the process stream through the flow passageways within the reticulated
elements and through the void spaces between the reticulated elements when multiple
reticulated elements are used provides for effective flow distribution perpendicular to
the flow of the process stream through the process unit. This method can be applied
to process streams that are entering the process unit, at any location within the process
unit, at the exit from the process unit or any combination of these locations. This
method can be applied to process streams while concurrently providing for filtration
of contaminants from the process stream. This method can be applied to process
streams while concurrently performing catalytic reactions to partially or totally
remove or convert desired chemical species in the process stream.
[0019] An additional feature of the present invention can include the step of using
reticulated elements in a variety of shapes. The shapes can include substantially
spherical shaped balls, monoliths, squares, raschig rings, saddles, hollow cylinders,
perforated disks, disks, single sheets, and solid cylinders, among others. Each shape
can be sized to individual specifications. Sizes for the shapes used can include
substantially spherical balls of about 1/8 to 2-inch diameters; monoliths with widths of
about 1/8 to 2-inches and lengths of about 1/8 to 2-inches; squares with widths of about
1/8 to 2-inches and lengths of about 1/8 to 2-inches; raschig rings with inside diameters
of about 1/8 to 1 inch and outside diameters of about 1/4 to 1 1/2 inches, and heights of
about 1/4 to 2 inches; saddle shapes with radii of about 1/4 to 2 inches; hollow cylinders
having inside diameters of about 1/8. to 1 1/4 inches, outside diameters of about 1/4 to 2
inches, and heights of about 1/4 to 3 inches; and solid cylinders having diameters of
about 1/8 to 1 inch and heights of about 1/4 to 2 inches. Custom-made one-piece disks
or single sheet construction can be custom-fit to the physical configuration of a
reactor. A further feature of this aspect of the present invention is that the reticulated
elements can be formed in either a disk or single sheet, each optionally having
perforations. An additional feature of the present invention is that the reticulated
elements when constructed can be formed into a plurality of segments in order to form
an assembled sheet or disk that is custom-fit to the reactor's physical configuration.
[0020] An additional feature of the present invention can include the step of using
reticulated elements in a variety of porosities and pore sizes. The reticulated elements
can be manufactured such that they have a porosity of so many pores per inch ("ppi").
For example, this means that a reticulated element of 30 ppi will, when examined by
one skilled in the art, have on average 30 pores per inch. Given that there are about
25 millimeters per inch, the pore sizes of such a material would be just under one
millimeter. Pore size in this context is the general size of the cavity of the pore
recognizing that pores are not perfect spheres. Another important element of pore
size is the size of the window opening into the pore. It is this measure that determines
the size of the largest particle that be trapped or filtered within the pore. The porosity
range of the reticulated elements of the present invention are from 4 to 800 ppi. This
enables customization of the size and shape of the reticulated elements for the
application constraints including particulate loading and pressure drop constraints.
The pores of the reticulated elements can be in a range of about 6 millimeters to about
100 microns, each being defined by a plurality of web members forming a plurality of
flow passageways through the reticulated elements.
[0021] An additional feature of the present invention can include the step of using
reticulated elements with different pore sizes in the same process unit so as to remove
contaminant materials of a broad range of sizes. The materials of the present
invention can filter contaminants down to about 1 micron in size. Commercially
available retention materials are capable of trapping particles down to about 50
micron in size.
[0022] Another feature of the present invention advantageously provides providing a
plurality of reticulated elements over an entire length of a process unit. The plurality
of reticulated elements can be commingled throughout the process unit with a
catalyst, with multiple catalysts or with other materials, such as structured packing
materials and the like.
[0023] In accordance with another aspect of the present invention, tile step of
contacting the contaminated process stream with the reticulated elements may include
depositing a catalyst on the reticulated elements prior to contacting the contaminated
process stream. Another feature of this aspect of the present invention may include
the use of reticulated elements as a substrate having a substantially uniform coating of
a selected catalyst including a porous alumina coating with a Group VI-B metal or a
Group VIII metal, or both. Preferably, the Group VI-B metal is molybdenum and
preferably, the Group VIII metal is either nickel or cobalt. More preferably, the
Group VI-B metal and Group VIII metal are impregnated into the reticulated
elements. The method of the present invention is useful to extend the run life of the
catalyst bed. The catalytically active reticulated elements can be utilized to react
diolefins or other polymer precursors and also to act as a filter and as a flow
distributor. By filtering solids and partially reacting any polymer precursors, e.g.,
diolefins, fouling of the catalyst is reduced, effectively extending the run time of the
reactor.
[0024] In accordance with another aspect of the present invention, the filtration
method may include the step of filtering solid particulate material or sediments that
form within a process unit in order to reduce fouling or plugging of downstream
equipment. This aspect of the present invention may include the steps of providing
one or more reticulated elements; contacting a process stream containing the
particulate material or sediments with the reticulated elements; removing the
particulate material or sediments from the process stream; and providing a relatively
particulate material or sediments-free process stream for further processing. The
reticulated elements can be located at one or more locations within the process unit or
at the outlet of the process unit or a combination of both. This method of removing
sediments can also be used in distillation columns to provide a relatively sediment
free process stream for further processing. The method of the present invention for
filtering process streams in catalytic bed process units, when compared with prior art
methods, has the advantages of reducing the volume of retention materials required;
lowering capital costs; improving the filtration of the solid particular matter from the
feed streams; decreasing the pressure drop across the system; increasing run time of
the reactor; allowing for the use of catalysts that have higher activity, lowering
operating costs; increasing process safety; and reducing environmental concerns.

BRIEF DESCRIPTION OF DRAWING

[0025J In the drawing:
[0026] FIG. 1 is partial a cross-sectional side view of a single fixed catalytic bed
process unit showing a specific embodiment of the present invention;
[0027] FIG. 2 is a partial cross-sectional side view of a multiple fixed bed chemical
reactor showing another embodiment of the present invention;
[0028] FIG. 3 is a partial cross-sectional side view of a combustor-style regenerator
fluidized bed reactor showing an embodiment of the present invention;
[0029] FIG. 4 is a partial cross-sectional side view of a two-stage regenerator
fluidized bed reactor showing an embodiment of the present invention;
[0030] FIG. 5 is a partial cross-sectional side view of a radial flow reactor showing
another embodiment of the present invention;
[0031] FIG. 6 is a perspective view of a perforated disk made of reticulated material
in accordance with the present invention;
[0032] FIG. 7 is a perspective view of a saddle made of reticulated material in
accordance with the present invention;
[0033] FIG. 8 is a perspective view of a hollow cylinder made of reticulated material
in accordance with the present invention;
J0034] FIG. 9 is a perspective view of an example of a one-piece sheet made of
reticulated material in accordance with the present invention;
[0035] FIG. 10 is a perspective view of an assembled disk made of reticulated
material in accordance with the present invention;
[0036] FIG. 11 is a perspective view of balls made of reticulated material in
accordance with the present invention;
[0037] FIG. 12 is a perspective view of a solid cylinder made of reticulated material
in accordance with the present invention;
[0038] FIG. 13 is a perspective view of a hollow cylinder made of reticulated material
in accordance with the present invention;
[0039] FIG. 14 is a perspective view of a monolith made of reticulated material in
accordance with the present invention;
[0040] FIG. 15 is a partial cross-sectional side view of a distillation column showing
an embodiment of the present invention;
[0041] FIG. 16 is a perspective view of a layer of reticulated elements with a void
space between each reticulated element that is varied in accordance with the present
invention;
[0042] FIG. 17 is a graph comparing the pressure drop in distillate hydrotreaters with
the reticulated elements of the present invention installed to the pressure drop in a
distillate hydrotreaters with prior art, retention materials installed;
[0043] FIG. 18 is a graph illustrative of the effect of the present invention on the
pressure drop in naphtha hydrotreater units;
[0044] FIG 19 is a partial cross-sectional side view of a down-flow process unit with
multiple layers of reticulated elements to provide the methods of the present invention
at the entrance of the process unit, at two other locations within the process unit and at
the outlet of the process unit in accordance with an embodiment of the present
invention;
[0045] FIG. 20 is a partial cross-sectional view of a process unit with layers of
reticulated elements of differing porosities to enable filtering of contaminants with a
wide range of particle sizes in accordance with an embodiment of the present
invention;
[0046] FIG. 21 is a perspective view of a top and a bottom of a piece of a reticulated
element on which had been dripped water tinted with food coloring illustrating the
perpendicular flow distribution of the reticulated elements in accordance with the
present invention; and
[0047] FIG. 22 is a perspective view of a process unit with the reticulated elements of
the present invention randomly packed throughout an entire length of a catalyst bed
according to an embodiment of the present invention.
[0048] While the invention will be described in connection with the preferred
embodiment, it will be understood that it is not intended to limit the invention to that
embodiment. On the contrary, it is intended to cover all alternatives, modifications,
and equivalents, as may be included within the spirit and the scope of the invention as
defined by the appended claims.
DETAILED DESCRIPTION AND SPECIFIC EMBODIMENTS
[0049] With reference to FIG. 1, for treatment of a process stream a single fixed
catalytic bed process unit 22 with reticulated elements 15 in the shape of substantially
spherical balls 122 (FIG. 11) will be described, although as previously discussed other
shapes of the reticulated elements 15 may be used, as well as other process units . If
the process unit 22 is of a downflow configuration, the contaminated process stream
20 will enter the process unit 22 at the inlet 24. The invention may be used in either
fixed or fluidized catalytic bed process units. Preferably, the present invention is used
in one or more fixed beds, in either an upflow or downflow or radial flow
configuration. Preferably, the catalytic bed process units include hydrotreater,
hydrorefiner, hydrocracker, reformer, alkylation, dealkylation, isomerization,
esterification, and polymerization reactors. Contaminants typically found in the feed
stream include dirt, iron oxide, iron sulfide, asphaltenes, coke fines, soot, catalyst
fines, sediments or other entrained foreign particulate matter, salts in distillation
columns, particulates in gas streams, sulfur or sulfides from tail gas units, or polymer
precursors such as diolefins. A layer 26, preferably layers 26, 28, of reticulated
elements 15 is provided in the vessel in an amount sufficient to filter the contaminants
from the process stream 20 for as long as desired including, but not limited to, as long
as the catalyst within the reactor is sufficiently active to justify operation of the
reactor. Preferably, multiple layers 26, 28 can be provided wherein the size of the
reticulated elements 15 such as balls 122 is graduated from one size in layer 26 to
another size in layer 28 as the incoming process stream flows through the bed of
reticulated elements 15. Reticulated elements can include foam materials and
monolith materials. Foam materials generally have a random pattern, while the
monoliths have a more uniform partem. If a reticulated ceramic element is used, the
reticulated ceramic elements can be made from any commercially available materials,
for example, zirconia toughened alumina, commonly referred to as ZTA. ZTA is
available from Fiber Ceramics, Inc. headquartered in Cudahy, Wisconsin. An
exemplary monolith for use in the present invention is available from Corning, Inc.
headquartered in Coming, New York. The graduated sizing of the reticulated
elements 15 allows the filtering of a broad range of sizes of contaminants.
[0050] The present invention advantageously provides a method of removing
contaminants from a contaminated process stream. The method preferably is
performed by providing reticulated elements preferably randomly packed with a void
space between each reticulated element to enhance filtration of contaminants in such
a way that the decontaminated process stream may pass through the reticulated
material unimpeded. The present invention provides a method whereby the entirety
of the reticulated elements can be utilized to filter contaminants from the process
stream. In catalytic bed process units, the reticulated elements can be sized such that
the catalyst bed has exhausted its catalytic activity before the reticulated elements
have exhausted their ability to filter out contaminant particles. This method enables
use of the entire bed of reticulated elements, as opposed to current methods that
eventually clog the top six to twelve inches of the retention materials conventionally
available. With such materials, beds deeper than about one foot are essentially of no
use in removing particulate contaminants from process streams. Further, with such
materials, once the top of the bed is plugged, the pressure drop in the equipment
begins to escalate, requiring a shutdown to remove and replace the clogged materials
from the process unit.
[0051] Data has been collected from different process units that have experimented
with the reticulated elements of the present invention. The reticulated elements of the
current invention have performed dramatically better than conventional retention
materials available commercially.
Example 1 — Use in a Distillate Hydrotreater
[0052] Data was obtained from a refinery for four distillate lrydrotreaters in virtually
identical process conditions. Two of the hydiotreaters, A and B, contained
conventional reticulated materials, known as "ring grading systems." The remaining
two hydrotreaters, C and D, used the reticulated elements of the present invention.
FIG. 17 shows a comparison of the pressure drop of the four hydrotreaters using
conventional ring grading systems and the reticulated elements of the present
invention. As can be seen in the graph, the pressure drop remained low relative to
start-of-run pressure drop over a period in excess of 450 days in the C and D
hydrotreaters containing the reticulated elements, while the A and B hydrotreaters
using the conventional ring grading system showed a dramatic pressure increase after
only 200 days in service. The results of the pressure drop comparison can be seen in
Table 1. The contaminated process streams in the distillate hydrotreaters were
predominantly in a liquid phase. In the C hydrotreater, the differential pressure was
only 8 psi at 450 days. In the D hydrotreater, the differential pressure was only 0.5
psi at 450 days. The differential pressure for the A and B hydrotreaters was S2.5 psi
and 54 psi respectively. In comparison, the C and D hydrotreaters with the reticulated
elements of the present invention performed significantly better than the conventional
ring grading systems. The lower differential pressure associated with the reticulated
elements of the present invention allows the time between turnarounds to be extended
dramatically.

[0053] A typical pressure drop scenario is to have a low pressure drop for the first
months of operation, but then, at a time that is not predictable, the pressure increases
significantly over a relatively short period to a point where the unit must be shutdown
to remove the pluggage, replace the removed material and restart the unit This can
be problematic given the unpredictability of the event, the need to acquire
replacement materials with very short lead-time or to maintain sufficient extra
inventory of replacement materials or to extend the down-time to await delivery of
replacement materials. With use of the reticulated elements in accordance with the
methods described herein, the pressure drop remains low for a predictable period of
time based on the level of contaminants in the process stream and the capacity of the
reticulated elements loaded in the process unit. Sufficient reticulated elements may
be loaded such that the catalyst in the unit is exhausted before the reticulated elements
are saturated.
Example 2 - Use in a Naphtha Hydrotreater
[0054] Data was obtained from a refinery with four naphtha hydrotreaters. Three of
the hydrotreaters (A, B, and C) used conventional ring grading systems, while the
remaining hydrotreater (D) used the reticulated elements of the present invention.
FIG. 18 illustrates that comparative pressure drop between the four hydrotreaters. At
the end of 200 days, the unit with the reticulated elements D experienced minimal
pressure drop, i.e. -4 psi for hydrotreater D, compared to the pressure drop
experienced by the three units containing ring grading systems, i.e. 10 psi for
hydrotreater B and 22 psi for hydrotreater C. The contaminated process streams in
the naphtha hydrotreaters were predominantly in a vapor phase. The reticulated
elements of the present invention filtered efficiently and effectively while the
conventional ring grading systems became clogged.
[0055] Referring again to FIG. 1, unless otherwise noted, in addition to filtering the
contaminated process stream 20, the reticulated material 15 may also enable a
uniform distribution and flow of the incoming process stream 20 to the catalyst bed
32.
[0056] By passing the process stream through a plurality of flow passageways 120
(FIG. 9) defined by web members 123 (FIG. 9) of the reticulated material 15 in layers
26, 28, the incoming process stream 20 may also be distributed by subdividing the
incoming process stream into a plurality of smaller fluid streams and then
resubdividing, a plurality of times, lie smaller streams so that the incoming process
stream is spread uniformly across the fluid entry cross-section 34, taken along line 34
- 34, of the catalyst bed 32. The process stream 20 is reacted in the catalyst bed 32.
Preferably the catalyst bed 32 contains discrete solid catalyst particles 36.
[0057] For catalytic bed process units, methods of the present invention filter
particulate contaminants before they reach the catalytic bed. This allows for
increased efficiency of the catalyst bed since more of the surface area of the catalyst is
available for use as a catalyst when compared to systems with conventional retention
materials, such as the ring grading systems used in Examples 1 and 2. As a result,
smaller sized, more catalytically active catalyst elements can be used due to the lower
average pressure drop of the unit resulting in a gain in catalyst activity of about 10% -
15%.
[0058] The reticulated material 15 may be used to filter and retain particulates 36
from the outgoing process stream 38. Small particulate material 36 that may be
entrained in the outlet process stream may be filtered, or captured, from the process
stream 3S and retained by reticulated material layers 40, 42. Preferably, the size of
the reticulated material in layers 40, 42 is graduated from a size in layer 40 to another
size in layer 42 at the outlet 44 of the reactor 22. In addition, sediments of material
may form in the process unit, e.g., sediments formed by excessive hydrocracking of
residual oils, that may plug or foul downstream equipment. These sediments may be
filtered from the outgoing process stream 38 by the reticulated material 15.
Preferably, the size of the reticulated material in layers 40,42 is graduated from a size
in layer 40 to another size in layer 42 at the outlet 44 of the reactor 22. Alternately,
the invention may also be used in an upflow configuration wherein the contaminated
process stream 46 would instead enter the unit at 44 at the lower end 39 and the outlet
process stream 25 would exit the process unit at 24 at the upper end 47 of reactor 22.
[0059] As previously discussed, another advantage of the present invention is to react
activated or partially activated reticulated material 15 with polymer precursors in a
contaminated process stream 20. Condensation polymerization of diolcfins may
occur in the process unit 32 after the contaminated process stream 20 is heated,
generally prior to introduction into the process unit 22, thereby forming foulants in the
process unit 32 itself that may gum or plug the process unit 32. As the foulants form
in the process unit, they cannot be filtered from the contaminated process stream 20
before flowing across the fluid entry cross-section 34. Therefore, the layer or layers
26, 28, 40, 42 of reticulated material 15 may be coated with an alumina powder that
may also act as a substrate for catalyst materials to form partially activated reticulated
material. As used herein, an "activated support" means (1) a reticulated material that
has been impregnated with catalyst materials or (2) a reticulated material that may be
an oxide, nitride, or carbide of a metal or (3) a reticulated material that contains
zeolite or inorganic oxides, e.g., alumina, silica, silica-alumina, magnesia, silica-
magnesia or titania. As used herein, a "partially activated support" means an activated
support material that has been purposefully made less active or partially deactivated in
order to achieve a slower reaction rate or to partially react the materials contacted.
[0060] Coated reticulated material 15 may also be used, wherein the coating may
comprise one of several conventional catalysts. Alumina may be used as an active
coating, optionally but preferably, alumina may be used as a support to strengthen the
catalyst. The catalyst according to this invention preferably comprises a metal of
Group VI-B or a member of Group VHI, or both, impregnated into an alumina based
support. Accordingly, the catalyst may comprise at least one of chromium,
molybdenum and tungsten in combination with at least one of iron, nickel, cobalt,
platinum, palladium and iridium. The use of palladium is particularly useful in the
removal of acetylene and diolefms from ethylene, the removal of oxygen, and the
removal of hydrogen. Of the Group VI-B metals, molybdenum is most preferred.
The catalyst preferably will contain from about 2% to about 14% by weight of Group
VI-B metal. Of the Group VTJI metals, nickel and cobalt are most preferred. The
amount of Group VIII metal in the catalyst is preferably from about 0.5% to about
10% by weight.
[0061] With reference to FIG. 2, a multiple fixed catalyst bed process unit 46 having
two fixed catalyst beds 48, 50 with reticulated material 15 in the shape of saddles 126
(FIG. 7) will be described. The reactor 46 is illustrated in a downflow configuration,
wherein the contaminated process stream 51 will enter the unit 46 at the inlet 52 and
the outlet process stream 54 will exit the unit at the outlets 56, 60. A partially reacted
process stream 58 may be accumulated at the outlet 61 of the first fixed bed 48 and
withdrawn at the collector tray 60. The partially reacted process stream 58 may be
heated or quenched or otherwise treated before reintroduction into the reactor 46 as a
partially reacted process stream 62 at the mixing chamber 64. The partially reacted
process stream 58 may be removed for redistribution, heating, or other processing
steps as required before reintroducing the partially reacted process stream 62 into the
reactor 46 for reaction with a succeeding catalyst bed 50. An additional layer 70 of
reticulated material 15 may be provided for filtration and distribution to remove any
contaminants entrained from or formed by the processing equipment used in the
additional processing steps such as dirt, iron oxide, iron sulfide, asphaltenes, coke
fines, soot, catalyst fines, sediments or other entrained foreign particulate matter, salts
in distillation columns, particulates in gas streams, sulfur or sulfides from tail gas
units, or polymer precursors such as diolefins.
[0062] Layers 66, 68, 70 of reticulated material 15 are provided in the reactor 46
below the inlet 52 and mixing chamber 64 in an amount sufficient to filter the process
stream 51 and the partially reacted process stream 62. Preferably, the multiple layers
66, 68, 70 are provided such that the porosity of the reticulated material 15 is
graduated from a porosity in layer 66 to another porosity in layer 68 to another
porosity in layer 70 as the incoming contaminated process stream flows through the
reticulated material 15. Optionally, the present invention may be practiced with or
without conventional basket screens 72. Preferably, the fixed catalyst beds 48, 50
contain discrete solid catalyst particles 74.
[0063] Another feature of the present invention advantageously provides providing a
plurality of reticulated elements 15 over an entire length of a process unit. The
plurality of reticulated elements 15 can be commingled throughout the process unit
with a catalyst 19, as shown in FIG. 22.
[0064] As previously discussed, an advantage of the present invention is that it may
also be used to distribute the process stream. The process stream 51 may also be
distributed while being filtered by subdividing the incoming process stream into a
plurality of smaller fluid streams by passing the process stream through a plurality of
flow passageways 120 (FIG. 9) defined by the web members 123 (FIG. 9) of the
reticulated material 15; then resubdividing, a plurality of times, the smaller streams so
that the incoming process stream is spread uniformly across the fluid entry cross-
section of the catalyst bed 76. The feed 51 is then reacted in the catalyst bed 48,
before being withdrawn as a partially reacted process stream 58 at the collector plate
60. The method of filtration and distribution is then repeated for the partially reacted
process stream 62 as it flows into the mixing chamber 64 and passes through the
reticulated material layer 70.
[0065] Another feature of the present invention is that the reticulated material 15 may
also be used to capture and retain catalyst particles 74 from the outflowing partially
reacted process stream 58 and the reacted process stream 54. The reticulated material
126 in layers 78, 80 at the outlet 61 of the first fixed bed 48 and the reticulated
material 126 in layers 82, 84 at the outlet 56 of the second fixed bed 50 are used to
filter and retain catalyst particles 74 that may be entrained in the partially reacted
process stream 58 or reacted process stream 54. As discussed with reference to FIG.
1, for capturing and retaining catalyst 74 from a partially reacted or a reacted
outflowing process stream in either a single or a multiple fixed bed chemical reactor,
the reticulated material 15 is preferably graduated from a porosity to another porosity
as shown in FIG. 2 for layers 78, 80 and 82, 84, respectively for each bed 48, 50.
Optionally, the porosity of the reticulated material may also be graduated from small
pores to large pores. Alternatively, the porosity of the reticulated material may be
inversely graduated from large pores to small pores to filter sediments that may form
in the catalyst bed.
[0066] A further advantage of the present invention is that the reticulated material 15
may be activated of impregnated with catalytically active material to react with
polymer precursors in process streams 51, 62. As depicted in FIG. 2, layers 66,68, 70
of reticulated material 15 may contain an activated support including inorganic oxides
preferably selected from the group consisting of alumina, silica, silica-alumina,
magnesia, silica-magnesia or titania or zeolites preferably selected from me group
consisting of zeolite L, zeolite X, and zeolite Y, which may be added to the reticulated
material as a substrate for catalyst materials. Optionally, the reticulated material may
be impregnated with catalyst materials or the reticulated material may be an oxide,
nitride, carbide or boride of a metal as disclosed in U.S. Patent No. 5,399,535, which
is hereby incorporated by reference to the extent it is not inconsistent with the present
invention.
[0067] Activated or partially activated reticulated material as described above may be
used to control the hydrogenation rate of the diolefms or other polymer precursors to
prevent fouling or gum formation. When endothermic reactions require the addition
of heat to the partially reacted process stream 58, preferably the reticulated material
15 of layer 70 is also activated or partially activated. The invention may also be
practiced with coated reticulated material, wherein the coating may comprise one of
several conventional catalysts. Alumina may be used on an active coating or support.
The catalyst according to this invention preferably comprises a metal of Group VI-B
or a member of Group VTR, or both, impregnated into the reticulated material,
inorganic oxide or zeolite. Accordingly, the catalyst may comprise at least one of
chromium, molybdenum and tungsten in combination with at least one of iron, nickel,
cobalt, platinum, palladium and iridium. Of the Group VI-B metals, molybdenum is
most preferred. The catalyst preferably will contain from about 2% to about 14% by
weight of Group VI-B metal. Of the Group VIII metals, nickel and cobalt are most
preferred. The amount of Group VEQ metal in the catalyst is preferably from about
0.5% to about 10% by weight.
[0068] FIG. 3 illustrates a conventional combustor-style fluidized bed reactor 88, 90.
Layers 86, 92 of reticulated material 15 may be used in fluidized bed chemical
reactors 90 and in a combustor, or regenerator 88, to reduce entrance losses and
maldistribution of the vapor or air flows. The inlet air 94 to the combustor or
regenerator 88 is flowed through the reticulated material layer 86 to subdivide the
stream into a plurality of smaller flowing streams. The reticulated material 15 may be
a single circular disk 124 (FIG. 6) without the illustrated perforation 125; however it
may be an oval or square sheet 121 (FIG. 9), or any geometric configuration desired
including an assembled disk 134 (FIG. 10). Optionally, multiple disks 86, 92 (FIG. 3)
may be used. Also, the disk 124 (FIG. 7) or sheet 121 (FIG. 9) may optionally
contain perforations. The subdivision of the vapor or air flows may reduce the
turbulence of the incoming vapor or air streams, thus reducing the compressor
horsepower usage or allowing for an increase in flow rate, depending on the process
constraints of the particular combustor-style fluidized bed reactor (FIG. 3). A further
advantage of the present invention is that the subdivided vapor or air flows may more
uniformly distribute the vapor or air 94 throughout the combustor or regenerator 88.
In addition, another layer 92 of reticulated material 15 may be used to uniformly
distribute any fluffing vapors 96 used in the fluidized bed reactor 90.
[0069] Alternatively, in FIG. 4, which depicts a conventional two-stage regenerator
fluidized bed reactor 104, layers 98, 112 of the reticulated material 15 may be used
similarly as discussed in FIG. 3 for a single-stage combustor or regenerator. The
turbulent inlet air 102 to the combustor or regenerator first stage 108 is flowed
through the layer 98 of reticulated material 15 to subdivide the stream, preferably into
a plurality of smaller flowing streams. Preferably, the reticulated material 15 is a
single circular disk 124 (FIG. 6) without the perforations 125; however it may be an
oval or square sheet 121 (FIG. 9), or any geometric configuration desired including an
assembled disk 134 (FIG. 10). Optionally, multiple disks 98,112 (FIG. 4) may be
used. Also, the disk 124 (FIG. 7) or sheet 121 (FIG. 9) may optionally contain
perforations. Similarly, for the second-stage 110, the turbulent inlet air 106 may be
flowed through the layer 100 of reticulated material 15 to subdivide the stream into a
plurality of smaller flowing streams. The subdivision of the vapor or air flows may
reduce the turbulence of the incoming vapor or air streams, thus reducing the
compressor horsepower usage or allowing for an increase in flow rate, depending on
the process constraints of the two-stage regenerator fluidized bed reactor 104, 116. A
further advantage of the present invention is that the subdivided vapor or air flows
may more uniformly distribute the vapor or air throughout the combustor or
regenerator chambers 108, 110. In addition, another layer of reticulated elementsl 12
may be used to uniformly distribute any fluffing vapors 114 used in the fluidized bed
reactor 116.
[0070] With reference to FIG. 5, for treatment of a contaminated process stream in
vapor form, a radial flow fixed bed chemical reactor 94 with reticulated material 15 in
the shape of substantially spherical balls 122 (FIG. 11) is illustrated, although, as
previously discussed, other shapes may be used. The contaminated process stream in
vapor form 92 will enter the radial flow reactor 94 at the inlet 96. A layer 98 of
reticulated material 15, more preferably layers 98, 100 of reticulated material 15, is
provided in the vessel between the deflection baffle 102 and the scallop 104. The
layers of 98, 100 reticulated material 15 aid in filtering contaminants such as dirt, iron
oxide, iron sulfide, asphaltenes, coke fines, soot, catalyst fines, sediments or other
entrained foreign particulate matter, or polymer precursors such as diolefins entrained
in the contaminated vapor feed 92 before reaction in the fixed catalyst bed 108 and
discharge through the center pipe 110 as the reacted process stream 112. Also as
previously discussed, an advantage of the present invention is that the reticulated
material 15 may be used to capture and retain catalyst from outlet streams, shown
here in the unloading tubes 106.
[0071] The reticulated elements can be used to filter contaminants, such as sediments,
in other types of process equipment. FIG. 15 illustrates another embodiment of the
present invention. In this embodiment, reticulated elements 95 are used for removing
sediments, such as salts, in a distillation column 90. The method of filtering
sediments formed in process equipment preferably includes providing a layer of
reticulated elements packed with a void space between each reticulated element. The
void space is varied to enhance filtration of smaller contaminants on a surface of the
reticulated elements while allowing larger contaminants to pass through to prevent
pluggage of the layer of reticulated elements. The method further provides for
contacting a process stream containing the sediments with the reticulated elements
thereby removing the sediments from the process stream by removing the smaller
contaminants on the surface of the reticulated elements and allowing the larger
contaminants to proceed through the void spaces between each reticulated element.
This method produces a relatively sediment-free process stream for further
processing.
[0072] FIG. 6 illustrates a specific embodiment of the present invention as a
reticulated elements disk 124. Optionally, the disks may have perforations 125.
Preferably^ multiple perforations are used to accommodate screen baskets that may
optionally be filled with reticulated elements. Other shapes may include saddles 126
(FIG. 7), hollow cylinders 128 (FIG. 8), single sheets 121 of reticulated material 15
(FIG. 9), disks 134 formed from a plurality of segments 134 a-f (FIG. 10),
substantially spherical balls 122 (FIG. 11), solid cylinders 132 (FIG. 12), raschig rings
130 (FIG. 13), squares (FIG. 14), and monoliths (FIG. 14). Each shape may be sized
to individual specifications. Sizes for the shapes used may include substantially
spherical balls of about Vt to 2 inch diameters; raschig rings with inside diameters of
about Vt to 1 inch and outside diameters of about lA to 1 1/2 inches and heights of
about 'A to 2 inches; saddle shapes with radii of about 'A to 2 inches; hollow cylinders
having inside diameteis of about % to VA inches, outside diameters of about lA to 2
inches, and heights of about lA to 3 inches; and solid cylinders having diameters of
about Vs to 1 inch and heights of about lA to 2 inches. Custom-made one-piece disks
124 or single sheet 121 construction may be custom-fit to the physical configuration
of a reactor. A further feature of this aspect of the present invention is that the
reticulated material 15 may be formed in either a disk 124 or single sheet 121 having
perforations 125. An additional feature of the present invention is that the reticulated
elements when constructed may be formed into a plurality of segments in order to
form an assembled sheet or disk that is custom-fit to the reactor's physical
configuration. Porosities of the reticulated elements may range from 4 to 800 ppi.
Preferably, the porosity may range from about 4 to 80 ppi. More preferably, the
porosity may range from about 10 to 60 ppi. This enables customization of the size
and shape of the reticulated material 15 for the application, size, particulate loading
and pressure drop constraints. The reticulate element material surrounding the pores,
or openings, of the reticulated elements form the web members 123 (FIG. 9), which in
turn define the flow passageways 120 (FIG. 9).
[0073] The present invention also advantageously provides a method of perpendicular
flow distribution in process units. This perpendicular flow distribution method
includes providing one or more reticulated elements in the process unit When only
one reticulated element is used, it is typically large enough to effectively span the
process unit. When multiple reticulated elements are used, they are typically arranged
in a randomly packed bed. Regardless of the configuration of the reticulated
elements, each reticulated element has a plurality of web members that define a
plurality of flow passageways through the reticulated element. A process stream
contacted with the plurality of reticulated elements is therefore subdivided into a
plurality of smaller fluid streams by passing the process stream through the plurality
of flow passageways defined by the web members of each reticulated element. The
flows of the process stream through the flow passageways within the reticulated
elements and through the void spaces between the reticulated elements when multiple
reticulated elements are used provides for effective flow distribution perpendicular to
the flow of the process stream through the process unit. This method can be applied
to process streams that are entering the process unit, at any location within the process
unit, at the exit from the process unit or any combination of these locations, as
illustrated in FIG. 19. This method can be applied to process streams while
concurrently providing for filtration of contaminants from the process stream. This
method can be applied to process streams while concurrently performing catalytic
reactions to partially or totally remove or convert desired chemical species in the
process stream.
(0074 J FIG. 21 illustrates the amount of perpendicular flow that the reticulated
elements of the present invention are capable of producing. An experiment was
performed using a dropper with a dropper diameter of approximately 1/16". The
reticulated element distributed the liquid perpendicularly to a diameter of about seven
times the diameter of the dropper. The flow was not distributed down the reticulated
element as much. The significant distribution was made in the horizontal plane and
not a vertical plane. When used in process units, the reticulated elements significantly
perpendicularly disperses the fluid to prevent channeling and other problems
discussed herein.
[0075] An additional feature of the present invention can include the step of using
reticulated elements in a variety of porosities and pore sizes, as shown in FIG. 20.
The reticulated elements can be manufactured such that they have a porosity of so
many pores per inch ("ppi"). For example, this means that a reticulated element of 30
ppi will, when examined by one skilled in the art, have on average 30 pores per inch.
The pore sizes of such a material would be just under one millimeter. Pore size in this
context is the general size of the cavity of the pore recognizing that pores are not
perfect spheres. Another important element of pore size is the size of the window
opening into the pore. It is this measure that determines the size of the largest particle
that be trapped or filtered within the pore. The porosity range of the reticulated
elements of the present invention are from 4 to 800 ppi. This enables customization
of the size and shape of the reticulated elements for the application constraints
including particulate loading and pressure drop constraints. The pores of the
reticulated elements can be in a range of about 6 millimeters to about 100 microns,
each being defined by a plurality of web members forming a plurality of flow
passageways through the reticulated elements.
[0076] As an advantage of the present invention, the filtering method provides for
more efficient filtration within the process unit. Since the contaminants do not cake
up on the first inches of the reticulated elements, as with conventional retention
materials, all of the filter bed can be effectively used. Pressure drop through the
reticulated elements can remain low as long as sufficient reticulated elements are
utilized such that the process unit reaches an end-of-run condition other than pressure
drop increase. The lower pressure drop increases the safety of operating the unit since
downstream equipment is not deprived of flow and the upstream equipment does not
pressure up. The run times between catalyst changes are significantly increased since
the process equipment can operate much longer than with previous filtration methods
before the process equipment end-of-run conditions.
[0077] Another advantage of the present invention is that smaller sized catalysts can
be used in catalyst bed process units since the catalyst bed is subjected to a much
lower cycle-average pressure drop. The result of using the smaller, more catalytically
reactive catalyst is a gain in activity of about 10% to about 15%. The entire surface
area of the catalyst can be used for its intended purpose, which is to modify and
increase the rate of a reaction, due to a much lower average pressure drop per cycle
for the process unit.
[0078] Another advantage of the present invention is, as depicted in FIG 21, the use
of one or more layers of reticulated elements at various locations within a process unit
to facilitate perpendicular flow redistribution to mitigate channeling and other
symptoms of flow maldistribution. Such one or more layers of reticulated elements
within a process unit also facilitate filtration of particulate contaminants within the
process unit.
[0079] It is to be understood that the invention is not to be limited to the exact details
of construction, operation, exact materials, or embodiments shown and described, as
obvious modifications and equivalents will be apparent to one skilled in the art. For
example, special liquid distributors or conventional liquid distributors could be used
the reticulated elements to facilitate the spreading of the liquid across process
equipment. Conversely, the reticulated elements could be used only for particulate
removal. Accordingly, the invention is therefore to be limited only by the scope of
the appended claims.
WE CLAIM:
1. A method of removing contaminants from a contaminated process stream
comprising the steps of:
(a) providing a plurality of reticulated elements in a process unit;
(b) randomly packing the plurality of reticulated elements within the
process unit thereby providing a void space between a substantial
number of the reticulated elements to enhance filtration of
contaminants on a surface of the plurality of reticulated elements
to produce a substantially decontaminated process stream; and
(c) contacting the contaminated process stream with the plurality of
reticulated elements to remove contaminants from the
contaminated process stream while allowing the substantially
decontaminated process stream to pass unimpeded through the
plurality of reticulated elements wherein the contaminated process
stream is a contaminated non-organic based process stream.
2. The method of claim 1, wherein the plurality of reticulated elements have
different pore sizes so that the plurality of reticulated elements can filter
contaminants of different sizes.
3. The method of claim 3, further including depositing a catalyst on the
plurality of reticulated elements prior to contacting the contaminated
process stream.
4. The method of claim 1, wherein the reticulated elements comprise a
material selected from the group consisting of a ceramic material, a
metallic material, and a chemical vapor deposition material.
5. The method of claim 1, wherein a substantial number of the plurality of
reticulated elements have a plurality of pores defined by a plurality of
web members forming a plurality of flow passageways through the
plurality of reticulated elements and an average pore size of the pores is
6 millimeters to 100 microns.
6. The method of claim 1, wherein the plurality of reticulated elements have
a porosity of 4 to 800 pores per linear inch.
7. The method of claim 1, wherein the reticulated elements are formed from
a reticulated foam material.
8. The method of claim 1, wherein the reticulated elements have a shape
selected from the group consisting of substantially spherical shaped
balls, raschig rings, saddle shaped pieces, monoliths, squares, a single
sheet, hollow cylinders, solid cylinders, and a single disk.
9. The method of claim 9, wherein the reticulated elements are formed
having perforations.
10. The method of claim 1, wherein the process unit has an inner cross-
sectional configuration and the plurality of the reticulated elements are
formed into an assembled sheet that, when constructed, is custom-fit to
the process unit's inner cross-sectional configuration.
11. The method of claim 1, wherein the process unit has an inner cross-
sectional configuration and the plurality of the reticulated elements are
formed into a plurality of segments forming an assembled disk that,
when constructed, is custom-fit to the process unit's inner cross-
sectional configuration.
12. The method of claim 1, wherein the process unit is selected from the
group consisting of a distillation column, a tail gas treater, an
incinerator, and a scrubber.
13. The method of claim 1, wherein the reticulated elements comprise a
substrate of reticulated elements having a substantially uniform coating
of a selected catalyst including a porous alumina coating with one Group
VI-B metal.
14. The method of claim 14, wherein the Group VI-B metal is molybdenum.
15. the method of claim 1, wherein the reticulated elements comprise a
substrate of reticulated elements having a substantially uniform coating
of a selected catalyst including a porous alumina coating with one Group
VIII metal.
16. The method of claim 16, wherein a Group VIII metal is nickel or cobalt.
17. The method of claim 1, wherein a Group VI-B metal is impregnated into
the reticulated element.
18. The method of claim 1, wherein a Group VIII metal is impregnated into
the reticulated element.
19. The method of claim 1, wherein the reticulated elements comprise a
porous inorganic oxide selected from the group consisting of alumina,
silica, silica-alumina, magnesia, silica-magnesia and titania.
20. The method of claim 1, wherein the reticulated elements comprise a
metal oxide selected from the group consisting of titanium, tin, lead,
zirconium, ruthenium, tungsten, yttrium, nickel, magnesium, calcium,
aluminum, silicon or boron.
21. The method of claim 1, wherein the reticulated elements comprise a
metal nitride selected from the group consisting of titanium, zirconium,
tungsten, silicon or boron.
22. The method of claim 1, wherein the reticulated elements comprise a
metal carbide selected from the group consisting of titanium, zirconium,
tungsten, silicon or boron.
23. The method of claim 1, wherein the reticulated elements comprise a
metal boride selected from the group consisting of titanium, zirconium or
tungsten.
24. The method of claim 1, wherein the reticulated elements comprise a
zeolite selected from the group consisting of zeolite L, zeolite X and zeolite
Y.
25. A method of perpendicular flow distribution in a non catalytically reactive
process unit comprising the steps of:
(a) providing a plurality of reticulated elements in a non catalytically
reactive process unit having a plurality of web members that define
flow passageways that facilitate perpendicular flow distribution;
and
(b) contacting a process stream with the zone of reticulated elements;
and
(c) subdividing the process stream into a plurality of smaller fluid
streams by passing the process stream through the plurality of
flow passageways defined by the web members of the plurality of
reticulated elements so that the process stream is significantly
dispersed in a perpendicular direction.
26. The method of claim 26 further comprising the following steps:
(a) removing contaminants from the contaminated process stream by
randomly placing the plurality of reticulated elements within the
process unit thereby providing a void space between each
reticulated element to enhance filtration of contaminants on a
surface of the plurality of reticulated elements; and
(b) providing a decontaminated and uniformly spread process stream
for further processing in downstream process unit.
27. The method of claim 26, wherein the step of providing a plurality of
reticulated elements includes providing the plurality of reticulated
elements at a location selected from the group consisting of a process
unit inlet, an interior of a process unit, a process unit outlet, and
combination thereof.
28. The method of claim 26, wherein the process unit has an inner cross-
sectional configuration and the plurality of the reticulated elements are
formed into an assembled sheet that, when constructed, is custom-fit to
the process unit's inner cross-sectional configuration.
29. A method of filtering sediments formed within a non catalytically reactive
process unit, the method comprising the steps of:
(a) providing a plurality of reticulated elements in a non catalytically
reactive process unit;
(b) randomly packing the plurality of reticulated elements within the
process unit thereby providing a void space between a substantial
number of the reticulated elements to enhance filtration of
contaminants on a surface of a substantial number of the
reticulated elements to produce a substantially sediment-free
process stream;
(c) contacting a process stream containing the sediments with a
substantial number of the reticulated elements;
(d) removing the sediments from the process stream; and
(e) providing a substantially sediment-free process stream for further
processing.
30. A reactor assembly comprising a reactor, the reactor including
(a) a plurality of reticulated elements randomly packed within the
reactor thereby providing a void space between a substantial
number of the reticulated elements to enhance filtration of
contaminants on a surface of a substantial number of the
reticulated elements to produce a substantially decontaminated
non-organic based process stream; and
(b) a catalyst bed located downstream of the plurality of reticulated
elements, the catalyst bed including an effective size of catalyst to
provide an increase in catalyst activity in a range of 15% to 20%.
31. The reactor assembly of claim 31, wherein the plurality of reticulated
elements are randomly packed throughout an entire length of a process
unit.
32. The reactor assembly of claim 32, wherein the plurality of reticulated
elements are commingled with catalyst over an entire length of a process
unit.
33. A method of removing contaminants from a contaminated process stream
comprising the steps of:
(a) providing a plurality of reticulated elements in a non
catalytically reactive process unimpeded;
(b) randomly packing the plurality of reticulated elements within
the chemical reactor thereby providing a void space between a
substantial number of the reticulated elements to enhance
filtration of contaminants on a surface of a substantial number
of the reticulated elements to produce a substantially
decontaminated process stream; and
(c) contacting the contaminated process stream with a substantial
number of the reticulated elements to remove contaminants
from the contaminated process stream while allowing the
substantially decontaminated process stream to pass
unimpeded through the plurality of reticulate elements.


A method for removing contaminants from a process stream that
includes the use of reticulated material to filter the process stream. The reticulated
material also facilitate process stream flow distribution in process units. The reticu-
lated material can be packed with a void space between a substantia] number of the
reticulated material that can be varied to enhance filtration and flow distribution.
The method of filtering also provides a method of removing contaminants leaving
process equipment. The methods can be used on a variety of process streams and
process equipment. The reticulated material can include ceramics, metallic mate-
rials, and chemical vapor deposition elements. The reticulated material can be of
various shapes and sizes, and can also be catalytically active.

Documents:

01979-kolnp-2005-abstract.pdf

01979-kolnp-2005-claims.pdf

01979-kolnp-2005-description complete.pdf

01979-kolnp-2005-drawings.pdf

01979-kolnp-2005-form 1.pdf

01979-kolnp-2005-form 2.pdf

01979-kolnp-2005-form 3.pdf

01979-kolnp-2005-form 5.pdf

01979-kolnp-2005-international publication.pdf

1979-KOLNP-2005-ABSTRACT-1.1.pdf

1979-KOLNP-2005-AMANDED CLAIMS-1.1.pdf

1979-KOLNP-2005-AMANDED CLAIMS.pdf

1979-KOLNP-2005-ASSIGNMENT.pdf

1979-KOLNP-2005-CANCELLED PAGES.pdf

1979-KOLNP-2005-CORRESPONDENCE 1.1.pdf

1979-KOLNP-2005-CORRESPONDENCE.pdf

1979-KOLNP-2005-DESCRIPTION (COMPLETE)-1.1.pdf

1979-KOLNP-2005-DRAWINGS-1.1.pdf

1979-KOLNP-2005-EXAMINATION REPORT 1.1.pdf

1979-KOLNP-2005-FORM 1-1.1.pdf

1979-KOLNP-2005-FORM 18.pdf

1979-KOLNP-2005-FORM 2-1.1.pdf

1979-KOLNP-2005-FORM 26.pdf

1979-KOLNP-2005-FORM 3-1.1.pdf

1979-KOLNP-2005-FORM 3.pdf

1979-KOLNP-2005-FORM 5-1.1.pdf

1979-KOLNP-2005-FORM 5.pdf

1979-KOLNP-2005-FORM-27.pdf

1979-KOLNP-2005-GRANTED-ABSTRACT.pdf

1979-KOLNP-2005-GRANTED-CLAIMS.pdf

1979-KOLNP-2005-GRANTED-DESCRIPTION (COMPLETE).pdf

1979-KOLNP-2005-GRANTED-DRAWINGS.pdf

1979-KOLNP-2005-GRANTED-FORM 1.pdf

1979-KOLNP-2005-GRANTED-FORM 2.pdf

1979-KOLNP-2005-GRANTED-SPECIFICATION.pdf

1979-KOLNP-2005-OTHERS.pdf

1979-KOLNP-2005-PETITION UNDER RULE 137.pdf

1979-KOLNP-2005-REPLY TO EXAMINATION REPORT 1.1.pdf

1979-KOLNP-2005-REPLY TO EXAMINATION REPORT.pdf

abstract-01979-kolnp-2005.jpg


Patent Number 250451
Indian Patent Application Number 1979/KOLNP/2005
PG Journal Number 01/2012
Publication Date 06-Jan-2012
Grant Date 04-Jan-2012
Date of Filing 06-Oct-2005
Name of Patentee CRYSTAPHASE INTERNATIONAL, INC.
Applicant Address 16945 NORTH CHASE DRIVE, SUITE 1610, HOUSTON, TX 77060-6029 UNITED STATES OF AMERICA
Inventors:
# Inventor's Name Inventor's Address
1 GLOVER, JOHN, N. 16418 GRAVEN HILL, SPRING, TX 77379 UNITED STATES OF AMERICA
PCT International Classification Number B01D 46/42
PCT International Application Number PCT/US2004/006366
PCT International Filing date 2004-03-02
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10/396,851 2003-03-25 U.S.A.